Cyano acetamino color couplers



Patented May 9, 1950 CYANO ACETAMINO COLOR COUPLERS Ilmari F. Salminen and Arnold Weissherger, Rochester, N. Y., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application February 8, 1947, Serial No. 727,298

9 Claims.

This invention relates to photography and particularly to compounds which form dyes by cou pling with the developing agent to produce colored images.

It is" known that colored photographic images may be formed by using a developer which pro duces a colored compound on development. The colored compound thus formed is deposited adja cent the silver grains of the silver image during the developing. It is also known that a colored image may be formed by adding to certain developer solutions or by incorporating in the silver halide emulsion before or after exposure a compound which couples during development with the oxidation product of the developing agent and forms a colored compound which is likewise deposited adjacent the silver grains of the silver mary aromatic amino developing agent and a coupler as hereinafter defined and also includes a new or improved color development process which consists in developing a reducible silver salt image in a photographic element with the aid of a primary aromatic amino developer and in the presence of a coupler as hereinafter defined. It also includes photographic sensitive elements having such coupler in one or more emulsion layers.

We have found that compounds of the following structure are valuable couplers for color pho-' where R is an aromatic nucleus or aromatic system and the position in the aromatic nucleus para or ortho to the hydroxyl group is unsubstituted with an irreplaceable group, that is, is unsubstituted or is substituted with a replaceable group such as chlorine.

The compounds of our invention are prepared by treating an aminophenol or aminonaphthol with ethyl cyano acetate, or with ethyl acetate or another suitable solvent, and cyano acetyl azide. Other substituent groups such as chlorine, bromine, methyl, ethyl, methoxy, ethoxy, etc., may be present in the aromatic nucleus as long as the position in the aromatic nucleus para to the hy-- droxyl group is unsubstituted or is substituted with a group which is replaceable in the coupling reaction.

Suitable amino phenols or amino naphthols which may be used in the preparation of our couplers are o-aminophenol, m-aminophenol, p-chloro o aminophenol, Z-amino 5 chlorophenol, 5-amino-l-naphthol, 4-chloro-5-aminol-naphthol and Z-amino-l-naphthol.

The compounds 2-cyanoacetaminophenol and 5-cyano-acetamino-l-naphthol illustrate couplers which may be used according to our invention. These couplers may be produced as follows:

2-CYANOACETAMINO PHENOL Method 1 v Method 2 To a finely divided mixture of 22 g. of o-aminophenol in 200 cc. of ethyl acetate was added 11 g. of cyanoacetylazide with stirring. The temperature of the mixture rose from 2632. It was evaporated to dryness and the tan residue stirred with 200 CC.'0Lf water and filtered. The moist residue was transferred to a beaker containing a solution of cc. of concentrated hydrochloric acid in 300 cc. of water. The mixture was stirred five minutes, filtered, washed on the funnel with water, and dried. Yield: 13 g.; M. P. l98-200. The product was recrystallized in white needles from ethyl acetate; M. P. 209-201.

5-CYANOACETAMIINO-1-NAPHTHOL continued at 195-205 for one-half hour, alcohol being collected. The reaction mixture was cooled and poured into cc. of ethyl ether. A small amount of gum was removed-by filtration. The

filtrate was treated with Darcd and filtered into 150 cc. of ligroin, the product being precipitated. This solid was filtered and crystallized from methanol and petroleum ether. Yield: 2.6 g.; M. P. 214-215.

The aromatic amino developing agents used with the coupler compounds of our invention include the mono-, diand tri-aminoaryl compounds and their derivatives formed by substitution in the amino group as well as in the ring such as alkylphenylenediamines and alkyltoluylenediamines. These compounds are usually used in the salt form, such as the hydrochloride or the sulphate, which are more stable than the amines themselves. Suitable compounds are diethyl-p-phenylenedi-amine hydrochloride, monoethyl pphenylenediaminehydrochloride, dimethyl p phenylenediaminehydrochloride and dimethyl -1pphenylenediamine, sulphate. De-

veloping agents containing heterocyclic systems.

as described in U. S. Patent 2,196,739 are also suitable. The p-aminophenols and their substitution products may also be used where the amino group is unsubstituted. All of these compounds have an unsubstituted amino group which enables the oxidation products of the developer to couple with the color-forming compounds to form a dye image.

The following example illustrates a developing solution which may be used with the compounds of our invention.

A. peAmino-diethylaniliue sulfate ,grams- 2 Sodium hydroxide (2% solution) -cc 50 For us jB is added to A -Qur development ,process may be employed for p du t on o or d pho g a h m e in ayer of gelatin or othe ca rier fo h s l halide such as collodion, organic esters of celluzl s or s th tic resins-c supp o t emulsion may be a ransparent mate ia s h as Ilass. cellulose ester or a znnn-rtransparent reliecting .material such as paper or an rpnaque -cellulose ester. .The iemulslon may be coated as a single layer on the support or as a superposed layer on one or both ,sidesof the support. The superposed layer may be differentially sensitized to some natural color photographic aimagesiin the well-known manner.

'The examples and compounds .set forth in the rpresent specification are illustrative .only and ;it .is to be understood that .our :invention-is limited .only .byithescope of-the appended claims.

Weclaim:

1. YA color-forming photographic developer comprising a primary aromatic :amino developing agent and a coupler rcompound :havlng the forwhere R'is selected from the:group consisting of aromatic nuclei-of the benzene and naphthalene series and the position in the aromatic nucleus para tothe' hydroxylgroup:contains=a substituent of the class consisting of hydrogen and a replaceable group.

"2. .A color-charming- :photographic developer comprising :aprimaryaromatic amino. developing egent and a. cOuplneomriophd-having :the formula:

3. A color-forming photographic developer comprising a primary aromatic amino developing agent and a coupler compound having the formula:

NHCOCHaCN 4. The method of producing a colored photographic image in a silver halide emulsion layer which comprises exposing said layer and developing it with a primary aromatic amino developing agent in the presence of a coupler compound having the formula:

agent in the presence of a coupler compound having the formula:

NHGOCHzCN The m od of pro ci a .celo ed hotographic image ,in a. silver halide emulsion layer which comprises exposing said layer and.devel opns -w th a prima y aromati amino d velo n agent in the presence of a coupler compound having the formula:

N oocrnoN 7. A photographic emulsion for forming colored images comprising asilver halide emulsion having incorporated thereinaicou pler compound .havingthe formula:

where R is selected from the group consisting of aromatic nuclei of the benzene-and naphthalene series and the position in the aromatic nucleus para to the hydroxyl group contains a substituent of-the class consisting of hydrogen and a-replaceable group.

8. A photographic emulsion for forming colored images comprising a silver halide emulsion having incorporated therein a coupler compound having the formula:

9. :A photographic .remulsion for forming col- :oredimages comprising asilver halide emulsion 5 having incorporated therein a coupler compound REFERENCES CITED having the formula: The following references are of record in the NHOOOHlON file of this patent:

6 UNITED STATES PATENTS Number Name Date 2,108,602 Mannes Feb. 15, 1938 2,441,491 Kendall et a1 May 11, 1948 H 10 FOREIGN PATENTS ILMARI F. SALMINEN. Number Country Date ARNOLD W'EISSBERGER. 576,891 Great Britain Apr. 25, 1946 

1. A COLOR-FORMING PHOTOGRAPHIC DEVELOPER COMPRISING A PRIMARY AROMATIC AMINO DEVELOPING AGENT AND A COUPLER COMPOUND HAVING THE FORMULA: 